The Annual Ball at the Metropolitan Museum of Art

When Petronius built the Temple of Dendur for Isis and Osiris around 15 B.C., did he know how on the mark he was? Because if you were at the Costume Institute Gala at the Metropolitan Museum of Art on Monday night, it was very clear that the gods still walk among us. Just take a look around the cocktail hour: Sir Paul McCartney playing a few chords on the grand piano, Mick Jagger extolling the virtues of the suit jackets Alexander McQueen made for his concert tours, supermodel Gisele Bündchen and Fergie of the Black Eyed Peas chatting about their shared neighborhood in Los Angeles (as their equally handsome husbands, Tom Brady and Josh Duhamel, respectively, looked on) and Beyoncé walking arm-in-arm with her husband Jay-Z. The gala—a mix of beautiful reverie and high culture—was this year celebrating the opening of the new exhibition “Alexander McQueen: Savage Beauty”—a look at the life and work of the visionary designer.

In his honor, the museum was decorated like a beautiful, romantic English garden with heather and wildflowers lining the great staircase, towering trees and hedges sprouting from the halls, and pots of garden roses and peonies haphazardly placed among glittering votives on rustic wood tabletops.

Kate Winslet and Madonna toured the breathtaking exhibition (on view from May 4 through July 31) like anthropologists, while the singer Rihanna had her own point of view after seeing the clothes. “I loved McQueen,” she said. “He was a rebel and that’s the purpose of fashion, to wear something and rebel. Otherwise, why bother?” Sarah Jessica Parker, who remembered how her dress matched his kilt when she attended the Costume Institute’s Anglomania exhibition and party in 2006 with McQueen as her date, agreed: “I loved him,” she said. “I just did.”

After cocktails in the Petrie Court, the sound of bagpipes filled the air as guests were summoned to a dinner that included artichoke, poached quail eggs, American caviar, Highland beef, and spring vegetables—and a performance by Florence + The Machine (choreographed brilliantly by the evening’s Music Director Baz Luhrmann) that had everyone on their feet.

“London might have the royal wedding, but we have this,” Mayor Michael R. Bloomberg told the 800-plus guests. “And this ticket is harder to get.” And never mind the Oscars, this is the international best-dressed convergence of the year. Colin Firth, the winner of this year’s Best Actor Academy Award, cochaired the event with Stella McCartney (honorary chairs were Salma Hayek and Francois-Henri Pinault) and appraised the crowd when he took the stage with a smile. “Just looking at you, I feel myself going up a size.”

As the dinner-table conversations continued, several guests slipped out of the museum and up Eighty-first Street where the party continued at Crown, chef John DeLucie’s not-yet-open hot spot on the Upper East Side, until the wee hours.